Many processes are known in the art for the carbonylation of olefinically or acetylenically unsaturated compounds. A review of such processes is provided by J. Falbe, "New Syntheses with Carbon Monoxide", Springer-Verlag, Berlin Heidelberg New York, 1980. Typically, the processes involve the reaction of an olefinically or acetylenically unsaturated compound with carbon monoxide and, in some cases, hydrogen or a nucleophilic compound having a removable hydrogen atom, in the presence of a carbonylation catalyst system. In many instances, the carbonylation catalyst system comprises a source of a Group VIII metal and a ligand such as a phosphine.
One type of catalyst system which has been disclosed in recent years comprises a source of a Group VIII metal and a pyridyl phosphine.
Kurti Kurtev et al, Journal of the Chemical Society, Dalton Transactions, 1980, pages 55 to 58 disclose catalyst systems comprising a rhodium or ruthenium compound and a pyridyl phosphine, and their use in the carbonylation of hex-1-ene.
European Patent No. A1-0259914 discloses catalyst systems comprising a palladium compound, a pyridyl phosphine, an acid and a quinone and their use in the carbonylation of olefins to afford polymers.
European Patent No. A1-0271144 discloses the use of catalyst systems comprising a palladium compound, a pyridyl phosphine and an acid in the carbonylation of acetylenes with hydroxyl-containing compounds.
European Patent No. A1-0282142 discloses the use of catalyst systems comprising a palladium compound, a pyridyl phosphine and an acid in the carbonylation of olefins with hydroxyl-containing compounds.
European Patent No. A1-0386833 discloses catalyst systems comprising a palladium compound and a (substituted-2-pyridyl) phosphine. As suitable substituents, hydroxyl, amino, amido, cyano, acyl, acyloxy, hydrocarbyl and hydrocarbyloxy groups; and halogen atoms are mentioned.
None of the aforementioned references describes experiments in which a catalyst system comprising a polyphosphino-substituted N-heteroaryl compound is used.
Newkome et al, J. Org. Chem., 43, 947 (1978), disclose the preparation of 2,6-bis(diphenylphosphino) pyridine.
It has now been found that carbonylation reactions can proceed at an extremely high rate using a catalyst system comprising certain polyphosphino-substituted N-heteroaryl compounds, particularly at a low ratio of the phosphine ligand to the catalyst metal component. Moreover, beta-carbonylated products may be obtained with remarkably high selectivity when an alpha-unsaturated hydrocarbon, in particular propyne, is carbonylated using such catalyst systems.